var _dataIndex;
Ext.grid.CheckColumn = function(config)  {   
	    Ext.apply(this, config);   
	    if(!this.id)  {   
	    this.id = Ext.id();   
	    }   
	    this.renderer = this.renderer.createDelegate(this);   
	};   
	Ext.grid.CheckColumn.prototype =  {   
		init : function(grid)  {   
		    this.grid = grid;   
		    this.grid.on('render', function()  {   
		    var view = this.grid.getView();   
		    view.mainBody.on('mousedown', this.onMouseDown, this);   
		    }, this);   
		},    
		  
		onMouseDown : function(e, t)  {   
		    if(t.className && t.className.indexOf('x-grid3-cc-'+this.id) != -1)  {   
		    e.stopEvent();   
		    var index = this.grid.getView().findRowIndex(t);   
		    var record = this.grid.store.getAt(index);
		    _dataIndex=this.dataIndex;
		    record.set(this.dataIndex, !record.data[this.dataIndex]);   
		    }   
		},    
		  
		renderer : function(v, p, record)  {   
		    p.css += ' x-grid3-check-col-td';   
		    return '<div class="x-grid3-check-col'+(v?'-on':'')+' x-grid3-cc-'+this.id+'"> </div>';   
		}   
	}  
	
	